In 1933 , working in ZÃ 1\/4 rich , Switzerland , Reichstein made vitamin C ( ascorbic acid ) in what is now called the Reichstein process . In 1933 , working in ZÃ 1\/4 rich , Switzerland , Reichstein succeeded , independently of Sir Norman Haworth and his collaborators in the United Kingdom , in synthesizing vitamin C ( ascorbic acid ) in what is now called the Reichstein process .