Novel fragmentation of 3-lithio-3,6-dihydro-1,2-oxazines: Synthesis of 2,5-dihydro-2-furanylamines
摘要:
N-Cbz or N-Boc protected 3,6-dihydro-1,2-oxazines 1 on treatment with LDA at -78-degrees-C undergo a novel rearrangement to provide synthetically useful N-Cbz or N-Boc protected dihydro-2-furanylamines 2.
Novel fragmentation of 3-lithio-3,6-dihydro-1,2-oxazines: Synthesis of 2,5-dihydro-2-furanylamines
摘要:
N-Cbz or N-Boc protected 3,6-dihydro-1,2-oxazines 1 on treatment with LDA at -78-degrees-C undergo a novel rearrangement to provide synthetically useful N-Cbz or N-Boc protected dihydro-2-furanylamines 2.
Asymmetric Diels-Alder reaction of the pentadienoic and hexadienoic acids 2a,b with the chiral chloronitroso derivative 3 gave the primary adducts 4a,b with good-to-excellent enantioselectivity. Subsequent as- or trans-dihydroxylation and hydrogenolytic cleavage of the NO bond led to the 5-amino-5-deoxypentono-δ-lactams 13a, 14, 15a, and 16 in the D-ribose, L-arabinose, D-xylose, and L-lyxose series