Radical cyclization of beta-aminoacrylates: synthesis of (-)-indolizidine 223AB.

[reaction: see text] (-)-Indolizidine 223AB was synthesized via radical cyclization of the beta-aminoacrylate derivative of a trans-2,5-disubstituted pyrrolidine. The trans-2,5-disubstituted pyrrolidine substrate was prepared by radical cyclization of a Ses-protected beta-aminoacrylate.

PTCA--the initial 100 cases in the Singapore General Hospital.

Percutaneous transluminal coronary angioplasty (PTCA) is an increasingly important technique for the treatment of patients with coronary artery disease. One hundred cases of PTCA were performed in Singapore General Hospital between 1985 to September 1988. 87% were males and 13% were females. The mean age of these patients were 55 +/- 9 SD years (range from 28 to 79 years). 85% had angina pectoris, 43% had a previous myocardial infarction and 12% received intravenous streptokinase previously. One hundred and twenty-nine lesions were dilated. 51% of the cases had single, 40% had double and 9% triple vessel disease. 83% had single, 16% double and 1% triple vessel dilatation. The distribution of the cases by vessel location was 64% for LAD, 19% for RCA and 17% for CX. Overall lesion success was 86%, with an increment in the success rate from 76% in 1987 to 89% in 1988. Similarly, the clinical success rate was 86% for the whole group; it increased from 74% to 90% from 1987 to 1988. The mean diameter stenosis was decreased from 86 +/- 14% SD predilatation to 28 +/- 28% SD postdilatation (p less than 0.005). The mean transtenotic gradient was reduced from 60 +/- 17 mmHg SD predilatation to 18 +/- 11 mmHg SD postdilatation (p less than 0.005). There were 14 failures (14%), the majority of which were due to inability transversing the lesion with a guide wire or balloon catheter. Fourteen complications (14%) occurred in these 100 cases of PTCA. 3% required emergent/semiemergent surgical revascularization. There was no mortality. PTCA is now an established mode of therapy for coronary artery disease in Singapore General Hospital.