Synthesis of Derivatives of the Optically Active β‐Amino Acids from (+)‐Car‐2‐ene

The reaction of (+)-car-2-ene (4) with chlorosulfonyl isocyanate (=sulfuryl chloride isocyanate; ClSO2NCO) led to the tricyclic lactams 6 and 8 corresponding to the initial formation both of the tertiary carbenium and α-cyclopropylcarbenium ions (Scheme 2). A number of optically active derivatives of β-amino acids which are promising compounds for further use in asymmetric synthesis were synthesized from the lactams (see 16, 17, and 19–21 in Scheme 3).