Direct Synthesis of ESBO Derivatives-¹⁸O Labelled with Dioxirane

Table 1

Mass spectrometry data.

Products	M (m/z)	Unlabelled	Labelled	^18O %^a
		M + 2	M + 2
Acetone^b	100 (58)	1.01	69.93	69%
Methyl-p-Tolil sulfoxide (3a)^b	100 (154)	5.91	13.88	8%
^18O-LLLox (2a)^c	100 (998)	23.23	64.71	42%
Acetone after DDO (1a) synthesis	100 (58)	1.01	21.02	20%

aThe percent of ¹⁸O was estimated form the 100×{[((M + 2)/M)_labelled – ((M + 2)/M)_unlabelled]}.
^bThe percent of ¹⁸O was determined using the GC/Ms analysis.
^cFor the ¹⁸O-LLL_ox was used the MALDI-TOF analysis.