You are using Science Of Synthesis as a Guest.
Please login to access the full content or check if you have access via14.4.10.1.2.1.1.1 Method 1: Cycloaddition of 3-(Phenylsulfinyl)-4H-1-benzopyran-4-ones and Danishefsky's Diene
Please login to access the full content or check if you have access via
Williams, A. C.; Camp, N., Science of Synthesis, (2003) 14, 604.
A cycloaddition–elimination sequence is used in the synthesis of 3-hydroxy-9H-xanthen-9-one (686) (Scheme 268).[1042] In this reaction, 3-(4-chlorophenylsulfinyl)-4H-1-benzopyran-4-one undergoes a cycloaddition with 1-methoxy-3-(trimethylsiloxy)buta-1,3-diene (Danishefsky's diene) in refluxing 1,2-dimethoxyethane to produce an intermediate that eliminates 4-chlorobenzenesulfenic acid and methanol to provide the desired product 686 as a single regioisomer in 50% yield.
Meeeee 888 8-Meeeeee-8M-eeeeeee-8-eee ee Meeeeeeeeeeee ee 8-(8-Meeeeeeeeeeeeeeeeee)-8M-8-eeeeeeeeee-8-eee eee Meeeeeeeeee'e Meeee[8888]
Meeeeee Meeeeeeee
8-Meeeeee-8M-eeeeeee-8-eee (8-Meeeeee-88M-eeeeeee[e,e]eeeee-88-eee) (888):[8888]
M eeee ee 8-(8-eeeeeeeeeeeeeeeeeeee)-8M-8-eeeeeeeeee-8-eee (888 ee, 8.88 eeee) eee 8-eeeeeee-8-(eeeeeeeeeeeeeee)eeee-8,8-eeeee (88%; 8.8 eM, 8.8 eeee) ee MMM (88 eM) eeeee M8, eee eeeeee eeeee eeeeee eee 88 e, eeeeee, eee eeeeeee ee ee eeee eee ee MMe (8 eM) eee 8 e. Mee eeeeeee eee eeee eeeeeee eeeeeeeee eeee e eeee ee MeMMM8 (8.8 e) ee M8M (8 eM), eee eeeeeeeeee. Mee eeeeeee eee eeeeeeeee eeee MM8Me8 (8 × 88 eM), eeeeee eeee M8M (8 × 88 eM), eee eeeee. Mee eeee eee eeeeeeeeee eee eee eeeeeeeee eeeee eeeeeeee eee eeeeeeeeee (MM8Me8/eeeeeeeee eeeee 8:8), eee eee eeeee eeeeeeeee eee eeeee ee eeeee, ee eeee eee eeeeeee; eeeee: 88.8 ee (88%); ee 888–888°M (MeMM/M8M).
References
[1042] | Meeeeee, M. M.; Meeeeeeeeeeee, M. M.; Meeeeee, M. M., Meeeeeeeeee, (8888) 88, 8888. |