Primary alcohols stannanes

The stannane was introduced using the directed ort/io-metalation reaction followed by addition of trimethyltin chloride to give 168. Hydroboration of arylstannane 168 with 9-BBN and oxidative work-up with basic peroxide provided the primary alcohol 169. Mitsunobu reaction of this alcohol with the cyanomethyl ester of 4-hydroxyphenoxyacetic acid afforded preactivated ester derivative 170 in good yield (Scheme 4.2.1). 

The stannane reduction is also applicable to selenocarbonates (2) of primary and secondary alcohols (equation II) and can result in the noralkane, the formate, or the... 

Alkenyl stannanes afford stable primary ozonides at — 78 °C in methanol, and their reduction at this temperature with BH3-SMe2 converts alkenes into 1,2-diols in good yields. Higher temperatures, longer reaction times, and solvents such as AcOEt or CH2C12 yield predominantly alcohols by splitting of the C=C bond <20020L383>. 

The synthetic utility of (i )-enoate 392 is illustrated in the stereoselective synthesis of the bengamide E derivative 399 (Scheme 88). Silyl protection of 392, reduction with DIBAL, and Sharpless epoxidation of the resulting allylic alcohol furnishes epoxy alcohol 396 as a 95 5 anti syn mixture. Conversion of the primary hydroxyl group of 396 to an iodide under neutral conditions followed by a metallation-elimination and subsequent in situ methylation provides the ether 397. Ozonolysis, desilylation with aqueous acetic acid, and a Dess-Martin oxidation supplies the a,jS-dialkoxy aldehyde 398. This, utilizing stannane Se addition, is then converted to 399 [135]. 

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