Regio-and stereospecific addition of chlorosulfonyl isocyanate to (+)-and (−)-α-pinene 1 resulted in enantiomerically pure β-lactams 2, which were converted to enantiomeric β- amino esters 3 and 1, 3-amino alcohols 4 and 6 with ee> 99%. The resulting 1, 3- difunctional compounds 3, 4 and 6 were transformed to fused saturated 1, 3-heterocycles such as tetrahydro-1, 3-oxazines 7 and 9, 2, 4-pyrimidinedione 11 and 2-thioxopyrimidin-4 ...