What Order To Draw Dashes And Wedges In

Yes, both inner and outer placements are possible with some nuances.

From Graphical representation of stereochemical configuration (IUPAC Recommendations 2006) [1, p. 1926]:

ST-1.3.two: Stereogenic centers at band fusion atoms

Stereogenic centers at ring fusion atoms should be drawn with hashed wedged or solid wedged bonds to the exocyclic substituent at the fusion cantlet whenever possible. If necessary, an implicit hydrogen should exist made explicit in order to provide an exocyclic substituent to comport the hashed wedged or solid wedged bond. When one of the fusion bonds is oriented vertically and the exocyclic substituent is graphically modest (such every bit a hydrogen or a methyl grouping, or fifty-fifty such physically larger substituents as a phenyl group represented with a graphically small "Ph" group label), the exocyclic substituent is as well preferentially oriented vertically and opposite to the vertical fusion bond. This orientation is preferred fifty-fifty if it results in the substituent being placed within the ring system, and is especially common in the depiction of steroids and other natural products.

From Graphical representation standards for chemical structure diagrams (IUPAC Recommendations 2008) [2, p. 354–357]:

GR-iv.2.2 Fusion atoms with ane substituent drawn

Ring fusion atoms already accept 3 bonds within the ring system. For external ring fusion atoms, the substituent should preferentially be positioned outside the ring system and oriented and then that it bisects the angle betwixt the adjacent bonds.

[...]

When two substituted fusion atoms are adjacent, placing both substituents outside the band arrangement volition typically cause them to overlap. In those cases, it is improve to draw one of the substituents inside the ring arrangement. A substituent drawn in this style should preferentially be fatigued exactly vertically or horizontally, whichever direction would minimize overlap with other atoms and bonds.

If a substituted fusion atom is adjacent to an unsubstituted fusion atom, there typically is enough room to orient the substituent either inside or outside the band system. That substituent should be oriented outside the ring system if all substituents can be oriented outwards, only should preferably be drawn exactly vertically or horizontally if whatever other substituent is placed within the ring organisation to avert disharmonize with an next substituent.

Small substituents on the C-eight and C-ix atoms of steroids should be fatigued within the ring system in this fashion fifty-fifty if in that location are no substituents on the side by side fusion atoms C-10 and C-14. Certain other natural products [23] also have preferred orientations that place substituents within the ring system.

A substituent should not be oriented within a ring system when attached to a fusion atom that lacks any vertical or horizontal fusion bond. The substituent should exist oriented outside the ring system, minimizing overlap every bit all-time as is possible. Sometimes, it might be possible to reorient the band system so that the fusion bonds are vertical; the substituents should certainly be placed vertically if so.

It is not acceptable to orient two substituents within the same ring if the band has fewer than eight atoms. I or both of the substituents should be oriented exterior the band arrangement, minimizing overlap as all-time as is possible.

Substituents on interior fusion atoms have no option other than being fatigued within the ring system. As above, such substituents should preferentially exist drawn exactly vertically or horizontally, according to the direction that would minimize overlap with other atoms and bonds.

References

1. Brecher, J. Graphical Representation of Stereochemical Configuration (IUPAC Recommendations 2006). Pure and Practical Chemistry 2009, 78 (10), 1897–1970. https://doi.org/10.1351/pac200678101897. (Free Access)
2. Brecher, J. Graphical Representation Standards for Chemical Structure Diagrams (IUPAC Recommendations 2008). Pure and Applied Chemistry 2009, eighty (2), 277–410. https://doi.org/ten.1351/pac200880020277. (Gratuitous Access)

Source: https://chemistry.stackexchange.com/questions/111394/does-the-location-of-line-dash-wedge-notations-matter

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