Sml2-mediated ring contraction

Sml2-mediated ring contraction of hexapyranoside derivatives to 5-membered carbasugars... 

Sinay et al. presented the Sml2-mediated ring contraction of methyl 6-unprotected-hexop)ra-noside derivatives to fully functionalized 5-membered carbosugars via the intermediate aldehyde shown in Fig. 19 [224]. The aldehyde [XXXVII], which was derived from the methyl... 

Using an approach that is conceptually similar to those described in Scheme 3.33, an a,p-unsaturated ester derivative of glucose has also been subjected to an S111I2-mediated ring contraction [70]. Treatment of 88 with Sml2 (5.0 equivalents) at 0°C in THF/MeOH (15/1) provided the cyclopentanol 89 as the sole product in an excellent yield (Scheme 3.34). 

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