The Claisen rearrangement of a spiro compound 1 derived from 1,2:5,6-di-O-isopropylidene-α-D-glucofuranose, with triethyl orthopropionate afforded the rearrangement products 4, 5, and 6 as a 1:2.5:10 diastereomeric mixture. The reaction of 1 with trimethyl orthobutyrate provided a 1:3 mixture of 7 and 8. In both cases, the σ-bond formation proceeded predominantly from the β-side. This stereochemical outcome was opposite to that observed in the case of the rearrangement of 1 with triethyl orthoacetate.
ASJC Scopus subject areas
- Organic Chemistry