Robert B. Shapiro, as former law professor turned corporate executive who performed a marketing miracle by branding aspartame as the sugar substitute NutraSweet, and making it a household name that consumers demanded in thousands of products, died on May 2 at his home in Chicago. He was 86.

Aspartame was invented by chemists at the pharmaceutical company G.D. Searle. In 1985, Searle sold $700 million worth of aspartame, identified as NutraSweet, to dieters and others wanting to avoid sugar. The product has no calories and, in spite of its name, no essential nutritional value,