This doesn't look like a traditional inversion of configuration: ![enter image description here][1] At first I dismissed the textbook author as making a typo. But then I realized that this "typo" was repeated throughout the solutions manual. So I tried drawing a Sawhorse projection of the textbook's answer and my answer, and I found that both are equivalent. So would my answer also be acceptable? In my answer I change the methyl from a wedge to dashes and the hydrogen from dashes to wedge and I place the SH group appropriately. ![][2] [1]: https://i.sstatic.net/RTxia.png [2]: https://i.sstatic.net/4qQby.jpg