3- Hydroxy-l-alkenyl carbamates

Hydroxy-l-alkenyl diisopropylcarbamates 2 (X = OCb), in this respect, occupy a medium position since they are stable in strongly acidic and basic protic solvents. For deblocking vinyl carbamates, the presence of catalytic amounts of mercuric or palladium(II) salts is required. Due to this stability, several reactions of homoallylic alcohols, proceeding with high diastereo-selectivity, e g., epoxidation, are applicable in order to introduce further hetero-substituents. 

Table 4. (Z)-4-Hydroxy-l-alkenyl Diisopropylcarbamates from ( )-2-Alkenyl Carbamates and Aldehydes...

Table 3. (4-Hydroxy-3-methvl-l-alkenyl) Carbamodithioates, Carbamothioates, and Carbamates by Aldehyde Addition to the Respective 2-Alkcnyllithium Derivatives...

Complete chirality transfer has been achieved in syntheses of 1-amino-2-hydroxy-3-alkenyl derivatives from (Z)-/ -substituted ally] sulfoxides, due to 1,3-allylic strain as an additional controlling factor. Stereochemically homogeneous 3,6-dihydro-l,2-thiazine oxides are easily obtained by hetero Diels-Alder reaction of A-sulfinyl carbamates and ( , )-2,4-hexadienes37 (see Section D.1.6.1.1.1.1.2.2). 

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